What is echolocation? Explaining how toothed whales ‘see’ the world

Requirements:
One stopwatch
One ball, preferably a basketball or kickball
One wall, preferably brick
Up to 25 feet of room

Explain to your students that toothed whales, such as the sperm whale, use echolocation to locate their prey or other objects in the water. The whales can determine the size and shape of an object as well as how far away it is by the ‘echo’ that returns to them after they emit a sound.

Experiment

Throw a ball at a wall with equal force from the following distances:
5 feet
10 feet
15 feet
20 feet
25 feet

Have a student record how long it takes the ball to return to the thrower from each distance.
Which throw bounced back in the least number of seconds?
Which throw bounced back after the greatest number of seconds?
What happens as you move away from the wall? What happens when you move closer to the wall?
Explain how this might relate to echolocation. Using echolocation, how do you think a whale can determine how far away an object is?